New approaches for the removal of catalysts from API suspensions

January 2019

The reference at a glance


Project description (initial situation, challenge etc.)


Candle or pressure plate filter depending on requirements




Removal of catalysts from pharmaceutical substances


Replacing manually operated filters with automated filtration solutions

The pharmaceutical industry has changed considerably. This is particularly the case for safety measures in the production of pharmaceutical substances (so-called APIs – Active Pharmaceutical Ingredients). This also applies to the removal of catalysts from API suspensions in particular, a processing step that has a direct impact on the quality of pharmaceutical products. BHS-Sonthofen supports companies from the pharmaceutical industry in using new filtration solutions that boast improved efficiency and reduce environmental impacts in the production of active ingredients.

Catalysts are commonly used in the production of APIs to trigger, accelerate or control reactions. Once the active pharmaceutical ingredient has been synthesized, these catalysts must be removed from the API suspension. Many companies are looking for new technological approaches to make the filtration of API suspensions more efficient and also safer. Real alternatives to conventional filters actually do exist.

New solutions for clarifying API suspensions are mostly based on candle and pressure plate filters. Both solutions have a lot in common: They are pressure filtration systems run in batches, and they are used in applications where liquids must be removed or solids recovered (e.g., catalysts) from liquids with a low ratio of solids. Compared to manual filters, both solutions offer a more reliable, efficient and optimized process, while at the same time reducing the risk to personnel and the environment. The ongoing operating costs are much lower to boot.

Candle and pressure plate filtration can remove particles with a size of 1–3 μm and enables precoat filtering. In many applications, candle filters can also remove finer particles up to 0.5 μm. Both systems use synthetic filter media. Pressure plate filters can also be used for metallic filter media, such as for high-temperature applications (above 200°C) or if steaming is required.